--- /dev/null
+As a special exception, the respective Autoconf Macro's copyright owner
+gives unlimited permission to copy, distribute and modify the configure
+scripts that are the output of Autoconf when processing the Macro. You
+need not follow the terms of the GNU General Public License when using
+or distributing such scripts, even though portions of the text of the
+Macro appear in them. The GNU General Public License (GPL) does govern
+all other use of the material that constitutes the Autoconf Macro.
+
+This special exception to the GPL applies to versions of the Autoconf
+Macro released by the Autoconf Archive. When you make and distribute a
+modified version of the Autoconf Macro, you may extend this special
+exception to the GPL to apply to your modified version as well.